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Topic: The 2019 melting season (Read 1045747 times)

Summer #seaice changes in the Chukchi Sea in the past 40 years have been profound. July 07 extent of 398000 km² is easily the lowest of record for the date. Prior to 1995, the majority of summers never saw this little ice in the Chukchi. #akwx #Arctic @Climatologist49 @ajatnuvuk

I've opened a special thread to specifically discuss the differences between 2012 and 2019. Be sure to read the rules, and please, post lots of maps, graphs and satellite images that show these differences.

In the meantime...Slater's model is pretty much unchanged the past few days.

Expected extent on Aug 27,2019: 4,31 M sq km

NSIDC extent on the same day of

2012: 3,942016: 4,772007: 4,832017: 5,00

Based on this, unless something extreme happens In July/Aug (superheat and or a big cyclone), it still looks like 2nd place for 2019.

What did the Slater model predict on this date for August 27, 2012? I'm betting that the prediction was more than 4.31Msqkm.

Slater's model does NOT include weatheranomalies so BY DESIGN it must overestimate extent in years of strong melting momentum/extreme weather. This should come as no surprise. And so, it did overestimate final extent both in 2007 and 2012 by about 0,5 M sq km in 2007 and 2012 as well. You can see model vs observation 1995-2012 here:

I'm not real knowledgable about this, but I'm assuming negative height anomaly over the Laptev increases likelihood and strength of surface lows and storms there, like the D9-10 cyclone in the EC. Terrible timing coming just as direct insolation starts to drop off.

The GFS is trending towards a cool Arctic and brutal heat over my head in the southeastern U.S.

There's no questioning Judah Cohen's interpretations of the model results, because they are correct, but the details make all the difference. The 384 hour GFS prog is very good for Arctic sea ice and very bad for me if I venture outside, but the GFS model is pretty bad at predicting weather over a week out.

If the GFS 384 hour prog verifies 2012 will likely take a solid lead over 2019, but I doubt the air over this Arctic will be as cool as the forecast output below.

I’m totally confused too. I think the take home message is that this is an expert interpreting long term model results. His interpretations are accurate, but long term models suck so we will wait and see what happens. 😝

ajouis, Agreed. A relatively large amount of solar energy has entered the arctic system so far this year.

I would even venture to say that 2019 started out too sunny in May, when clouds and moisture are more helpful for melt onset. This is why 2019 was trailing years like 2010, 2012 and 2016 in surface preconditioning during the first two weeks of June.

Neven, thank you. Your comment drives home my point. Which is, that while the major introduction of energy to the system comes from solar energy, the discussion here tends to focus on the weather. What happened to that solar energy added to the arctic system this year when it was 'too sunny'? Understood, the sunny weather conditions in May this year were not optimal for the humidity driven formation on melt ponds. But that intense solar energy must have gone somewhere. A large amount of it was not reflected due to albedo. It appears to have been absorbed into the system. Even though such events may not be reflected in relatively near term responses, it would seem that such addition of energy to the Arctic system is important.

I further suggest, that a key reason that what happens during the remainder of the Arctic Sea Ice melt season here in 2019 cannot be projected from historical results is that the fundamental properties of the system have changed.

Both the GFS and European models are trending towards a cool and stormy central Arctic ocean starting about 72 hours out. We'll see how this all plays out. Has the damage been done already or will cooler weather give the ice a reprieve? Or will the models fail to predict some critical thing?

Both the GFS and European models are trending towards a cool and stormy central Arctic ocean starting about 72 hours out. We'll see how this all plays out. Has the damage been done already or will cooler weather give the ice a reprieve? Or will the models fail to predict some critical thing?

Both the GFS and European models are trending towards a cool and stormy central Arctic ocean starting about 72 hours out. We'll see how this all plays out. Has the damage been done already or will cooler weather give the ice a reprieve? Or will the models fail to predict some critical thing?

Will that come down as rain or snow?

If it comes down as snow, I think we would all be shocked. Cooler cloudier weather this time of year means rain and storms. I’m not saying snow is impossible, but highly unlikely.

Judah Cohen appears to be anticipating a gradual shift towards a neutral or slightly negative AO for the remainder of the month (as opposed to more strongly negative in recent weeks), so this suggests average or slightly above average surface air pressures generally across the Arctic ocean.However, he is also suggesting that the NAO will remain in its negative state, which means higher air pressure around Greenland.

Looking at the anomaly charts for geopotential height, which you can roughly take as a guide to surface pressure patterns, high pressure remains around Greenland and stretching back towards the Beaufort sea, with low pressure across the Eurasian side of the Arctic.

6-10 day

11-15 day

Rather than a general period of storminess, this suggests a switch to a more dipole like patterns, which a chances of some depressions around the ESS, Laptev and Eastern side of the central Arctic ocean.While it might not bring the exceptional heat the last 2 months, the potential for compaction and export from such a fractured pack is very high, and leaves little reason to suggest the weather will save the ice.

Momentum across the board at the moment. We'll see if the forecasted cool weather can put the brakes on it.

Its not really that cool on the current GFS on Climate Reanalyser, Alaska and eastern Chukotka and the Pacific sector have no reprieve, the CAA stays warm, and massive heat build in Siberia ready to blast through the Laptev sea, if we're unlucky. And the storms will struggle to drop the surface to 0, its the warmest part of the year in the high arctic

380K drop in the past 3 days on JAXA, and that trajectory will continue for a bit as the Pacific and Eurasian fronts rapidly retreat and Hudson Bay and the Kara Sea expire. 2012 and 2016 both lag a bit over the next week or 2 so 2019 might be 300K or more if things go bad ahead in 2 weeks.

On JAXA in a fortnight on 22/7 the leader of the pack is 2007 on 7.02 )million km2, only 1.12 million ahead of today(or 81K per day - 2007 itself dropped 1.5 million km2 during this period) . Momentum and the next few days weather will keep 2019 well in front, at least for now

I have followed this forum for about a month, and read every post. Thank you everyone for contributing, there is a wealth of knowledge.

Here is a couple of animations of how the ice is declining (the first one including a one week forecast as well). The ice melts very quickly, multi year ice disappearing, 2m thick ice turning into 1.5 meter thick ice, 1.5 into 1 meter, 1 meter into 0.5m, etc. It seems like there won't be much ice left at the end of the melt season if this melt momentum continues. Especially with the decrease of albedo, as there will be more and more open sea.

For those interested in more details on volume, I've just posted PIOMAS July 2019 on the ASIB.

Much appreciated, sir. Slight note on wording there, PIOMAS section: instead of "escape the grey bands of standard deviation", i'd rather say "escape the lighter-grey band of 2nd standard deviation", unless it's wrong to think that each color corresponds to one standard deviation (i do). And to answer your question at the end of the piece: why, it's likely 2019 will beat 2012, due to simple consideration: volume (and thus amount) of ice is on par for the moment, but pace of the melt is greatly higher for 2019. Continue the trend, the answer is obvious. Of course, weather "may" have a say and "override" the trend, thus only "likely" above - not more. I guess that's the best answer there may be, at this time.

The GFS is trending towards a cool Arctic and brutal heat over my head in the southeastern U.S.

There's no questioning Judah Cohen's interpretations of the model results, because they are correct, but the details make all the difference. The 384 hour GFS prog is very good for Arctic sea ice and very bad for me if I venture outside, but the GFS model is pretty bad at predicting weather over a week out.

If the GFS 384 hour prog verifies 2012 will likely take a solid lead over 2019, but I doubt the air over this Arctic will be as cool as the forecast output below.

If there is one thing I'd bet my mortgage on not happening it's whatever the the GFS is showing at hour 384...

Looking at ground weather stations around the basin, it seems current temps are nothing to write home about - no location has a sustained heat wave for days on end like the Siberian side saw in June. OTOH, perhaps enough damage has been done already.Tiksi - Laptev coast near Lena delta.Pevek - ESS coast.Kotelny Island - border between Laptev, ESS, CAB.Barrow - coastal border between Chukchi and Beaufort.

Could any of this anomalous warming in the ESS and Alaska be from localized methane emissions? How soon does methane contribute warming once released?

<Edit Neven: Ask questions like this one in the 'stupid' questions thread, or the methane thread.>

With much respect, Neven, i have a related (to the above) question, for which i invariably need a certain much-more-than-5-lines length. Apologies. Complex issue, you know.

The question is: do you personally think that given the following data, interaction between methane emissions in ESAS (at least; possibly other arctic shelves) and local sea surface temperatures (and thus, sea ice melt rates) - should be discussed, among other things, in this here Melting Season topic - and, if you do not think so, then why, exactly, it should not be discussed here?

<Edit Neven: snipped a lot of text that clogs the thread. To answer your question: No, it shouldn't be discussed here, because this thread is for near-real time monitoring of conditions in the Arctic. If you can point to reliable near-real time data graphs or maps that have a direct influence on the outcome of this melting season, and that can be compared to previous years, please do so. If not, take it up in other threads.>

Sterks

Looking at ground weather stations around the basin, it seems current temps are nothing to write home about - no location has a sustained heat wave for days on end like the Siberian side saw in June. OTOH, perhaps enough damage has been done already.Tiksi - Laptev coast near Lena delta.Pevek - ESS coast.Kotelny Island - border between Laptev, ESS, CAB.Barrow - coastal border between Chukchi and Beaufort.

Pevek is +10C of anomaly, and maybe we could check it and Kotelny again tomorrow and the day after... But good observations anyway.PS what was the source by chance?

How positive is everyone that the arctic will indeed be impacted by a cooler, more conductive weather pattern of ice retention? Granted it's only a single point in a vast area, but temperatures are foretasted to remain in the 50f+ in Barrow (not implying that area is AT ALL indicative of the area at large). I will wait and see how the weather systems unfold, however I think the warm water inundating the Pacific side will continue to slowly erode that zone.

I really like the source - pogodaiklimat - because it has graphs of the past and not just a forecast like most weather sites. It compares with daily climatology. It shows a whole month at a time. And archives the graphs of past months and years that you can access at the bottom of the page.Downsides are that it's in Russian (Google translate to the rescue), and only covers Russia and ex-soviet states, world big cities and the USA (but not Northern Canada or Greenland).

July 8th, 2019: 8,135,012 km2, a century drop of -150,362 km2.2019 is the lowest on record. (2012 highlighted).

I remember about a month ago now maybe a couple guys from the sea ice area/extent thread called me out saying they didn't want my hyperbole mucking things up.

Uh huh.

One of them was me, not that I wanted to ban hyperbole. It's part of life's rich tapestry. Other people made a hoo-hah about it.

Since then, extent and area losses have been such that my prediction for a 2nd lowest JAXA daily extent minimum at or a bit below 4 million is looking a bit more likely. (In early June a minimum well above 4 million looked more like it).

Your own postings recently have suggested a moderation in extent and area loss in the immediate future.

The great questions remain: - will the remainder of July and August build on the "melting momentum" suggested by Neven, or will it just fade away,- will there be a GAC before September, and will it be huge, and will it impact sea ice ice as it did in 2012?

If yes, hyperbole wins and I slink away, tail firmly between legs.If no, and the JAXA minimum is, say, a couple of hundred k below 4 million, hyperbole loses, and I tell everyone how marvellous I am._________________________________________________________ps: While JAXA daily extent loss accelerates, NSIDC 5 day average area daily loss gently declines.A different story nearly every day.

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"Para a Causa do Povo a Luta Continua!""And that's all I'm going to say about that". Forrest Gump"Damn, I wanted to see what happened next" (Epitaph)

some would say this was set in motion months ago Friv .. NSIDC extent down 201,000 today . The old cold ice has gone west / south . The ice that enjoyed the mildest weather in winter has no staying power . As I said on March 1st , the choice this year is 1st or less likely 2nd . I have not changed my opinion thus far . b.c.

I think that his charts re: the atmosphere etc, as well as actual modeling, do NOT point to a long-term cooldown. Rather, they show the strat vortex descending into the surface level of the Arctic, which is essentially what the GAC was (IMO).

As we approach peak OHC, there is going to be an impetus for this to occur, and I think this is what is now showing up on the LR modeling. While heights may be lower, and temps may even cool a bit, it will be because of enormous / near-continuous development of a basin-spanning LP event, which will WRECK the ice most completely.

Research has shown conclusively than June melt ponding and momentum is basically the only thing that matters to the minimum (r2 = .91). The extension of that logic is that the events of 2012 were due to the momentum established that June. If 2019 follows the same rules, it will see a bigger / repeat "GAC" event, likely earlier in the season than 2012, due to the +OHC we have this year.

While that may translate into "cold" 500MB heights, it does NOT mean that melting momentum is going to decrease -- in fact, it may be the opposite.

We can revisit this post in 10 days and see if it is already snowing and the ice is being left alone and regenerating. If that is happening, you can call me wrong.

PS: the HYCOM projection was mostly accurate regarding the sudden and dramatic (and ongoing) collapse of the PAC front. Look for other peripheral areas to follow over the next week.

I’m totally confused too. I think the take home message is that this is an expert interpreting long term model results. His interpretations are accurate, but long term models suck so we will wait and see what happens. 😝

in case that exact model becomes true it will be very very windy in some places and as long as temps are above or around 0C and it's stormy, not much (nothing) is won.

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Rich

How positive is everyone that the arctic will indeed be impacted by a cooler, more conductive weather pattern of ice retention? Granted it's only a single point in a vast area, but temperatures are foretasted to remain in the 50f+ in Barrow (not implying that area is AT ALL indicative of the area at large). I will wait and see how the weather systems unfold, however I think the warm water inundating the Pacific side will continue to slowly erode that zone.

If the Arctic ice remaining to be melted was in Barrow, I'd be more concerned.

The ice front is now hundreds of kilometers offshore. It's the temperature there that counts.

It's still going to melt at 1-2C above freezing, but not at the same rate that we've been losing ice recently.

The advance of the Chuchki and Beaufort toward the CAB is poised to slow down. ESS and Laptev still have some legs. Periphery will disappear. Atlantic side can always make a move.

But the Pacific side is quite finite. That little opening at the Bering is a limiting factor.